Gold King Mine Data, September 18, 2015

EPA sediment samples collected on 9/10 through 9/14 from locations along the Animas and San Juan Rivers.

EPA has reviewed the data which includes comparison to screening levels for exposure during recreational use. The metal concentrations of the samples are below sediment/soil recreational screening levels, and are being maintained at pre-event conditions. Based on previous monitoring events it has been shown that metal concentrations may fluctuate from time to time because of water surges due to heavy rains or other events that may change the water flow rates or volume.

EPA surface water samples collected on 9/10 through 9/14 from locations in the Animas and San Juan Rivers.

EPA has reviewed the data which includes comparison to screening levels for exposure during recreational use. The metal concentrations of the samples are below surface water recreational screening levels, and are being maintained at pre-event conditions. Based on previous monitoring events, it has been shown that metal concentrations may fluctuate from time to time because of water surges due to heavy rains or other events that may change the water flow rates or volume.